Lightweight, robust, wear resistant components comprising an aluminum matrix composite

ABSTRACT

Rotor, disc, chain ring, and sprocket components are manufactured from a fine particle reinforced metal matrix composite material. The metal matrix composite may be an aluminum or aluminum alloy matrix. The fine reinforcement particles have a particle size from 5 microns to 0.3 microns. These reinforcement particles are dispersed in the matrix.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to U.S. Provisional Patent ApplicationSer. No. 62/134,185, filed on Mar. 17, 2015. The entirety of thatapplication is hereby fully incorporated by reference herein.

BACKGROUND

The present disclosure relates to fine particle reinforced aluminumalloys known as metal matrix composites which offer an enhancement innon-aggressive wear properties, providing a significant life increaseand performance improvement in articles made therefrom. This particlereinforced aluminum matrix composite material uses fine particle sizesin the range of about 0.3 microns up to about 5 microns. These particlereinforced aluminum matrix composite materials provide high strength toavoid tooth deformation, sufficient ductility to deal with robust usage,lightweight characteristics (for weight-dependent applications),non-aggressive wear resistance, and an ability to manufacture thecomponents using conventional machining processes.

Metal matrix composites are composite materials including a metal matrixand a reinforcing material (e.g., a ceramic material or an organiccompound) dispersed in the metal matrix. The metal matrix phase istypically continuous whereas the reinforcing dispersed phase istypically discontinuous. The reinforcing material may serve a structuralfunction and/or change one or more properties of the material. Metalmatrix composites can provide combinations of mechanical and physicalproperties that cannot be achieved through conventional materials orprocess techniques. These property combinations have made metal matrixcomposites particularly useful in the aerospace and other transportindustries.

Powder metallurgy is a process by which powdered materials are compactedinto a desired shape and sintered to produce desired articles. Powdermetallurgy allows faster quenching of the metal which typically resultsin smaller grain sized, increased solid solubility of most soluteelements, and reduced segregation of intermetallic phases. These resultsmay lead to beneficial properties in the produced articles, such as highstrength at normal and elevated temperatures, high modulus values, goodfracture toughness, low fatigue crack growth rate, good thermalconductivity, non-aggressive wear resistance and high resistance tostress corrosion cracking.

Aluminum alloys are typically used to make motorcycle and bicycle chainrings and sprockets. These sprockets suffer from wear against the drivechain, as well as wear attributable to the accumulation of grit, mud,dust, or the like, leading to abrasion-related degradation of the chainring or sprocket. Limitations on the type of aluminum alloy to be useddepend largely upon the application in which the sprocket is to be used.For example, bicycle and motorcycle components need to be lightweight,while retaining high strength for the drive train assemblies.Furthermore, advancements in brakes on small vehicles and bicycles haveled toward the adaptation of disc braking systems to road bicycles,which are much more efficient and effective than the traditionalcantilevered design. However, while disc brakes have increasedperformance over traditional cantilevered braking systems, widespreadadoption on racing bicycles has not occurred as the weight of the discis greater than that of the traditional designs. A lightweight disc isneeded to render the disc light enough for use on lightweight bikes.

It would be desirable to provide compositions and methods for producingarticles containing aluminum matrix composites having fine reinforcementparticles that overcome the aforementioned deficiencies.

BRIEF DESCRIPTION

The present disclosure relates to metal matrix composite materialsincluding a reinforcement phase dispersed in a matrix phase. The matrixphase includes aluminum or an aluminum alloy. The reinforcement phasemay include a reinforcement material having an average particle size inthe range of from about 0.3 μm to about 5 μm, and more particularlyabout 0.3 μm to about 3 μm. The present disclosure further relates tolightweight, strong and enhanced wear resistant articles made from suchmetal matrix composites, and in particular articles such as sprockets,chain rings, discs or rotors, which have relatively small cross-sectionsthat must withstand heavy wear. The reinforced aluminum alloy materialsdisclosed herein use reinforcement particles of about 0.3 μm to 7 μm insize, representing a substantial reduction in size of currentlyavailable reinforced aluminum alloys.

Disclosed in various embodiments are discs, rotors, sprockets and chainrings machined from metal matrix composites. The metal matrix compositeincludes an aluminum or aluminum alloy matrix; and reinforcementparticles dispersed in the matrix. The reinforcement particles have anaverage particle size in the range of about 0.3 μm to about 3 to 7 μm.

The reinforcement particles may include at least one ceramic materialselected from the group consisting of carbides, oxides, silicides,borides, and nitrides.

In some embodiments, the reinforcement particles comprises at least oneceramic material selected from the group consisting of silicon carbide,titanium carbide, boron carbide, silicon nitride, titanium nitride,aluminum oxide, and zirconium oxide.

The aluminum alloy may include at least one element selected from thegroup consisting of chromium, copper, lithium, magnesium, manganese,nickel, zinc, iron, vanadium, scandium, silver, and silicon.

In some embodiments, the aluminum alloy includes from about 91.2 wt % toabout 94.7 wt % aluminum, from about 3.8 wt % to about 4.9 wt % copper,from about 1.2 wt % to about 1.8 wt % magnesium, and from about 0.3 wt %to about 0.9 wt % manganese.

The aluminum alloy may include from about 95.8 wt % to about 98.6 wt %aluminum, from about 0.8 wt % to about 1.2 wt % magnesium, and fromabout 0.4 wt % to about 0.8 wt % silicon.

In some embodiments, the composite includes from about 15 vol % to about40 vol % of the reinforcement particles.

Also disclosed are methods for producing an article from a metal matrixcomposite material, comprising: cold compacting the metal matrixcomposite material to form a preform; hot compacting the preform toproduce a billet; and processing the billet to form the article; whereinthe metal matrix composite material comprises an aluminum or aluminumalloy matrix material with reinforcement particles dispersed therein,the reinforcement particles having an average size of from about 0.3 μmto about 5 μm.

In some embodiments, the reinforcement particles include at least oneceramic material selected from the group consisting of carbides, oxides,silicides, borides, and nitrides.

The reinforcement particles may include at least one ceramic materialselected from the group consisting of silicon carbide, titanium carbide,boron carbide, silicon nitride, titanium nitride, aluminum oxide, andzirconium oxide.

The aluminum alloy may include chromium, copper, lithium, magnesium,manganese, nickel, zinc, iron, vanadium, scandium, silver, or silicon.

The aluminum alloy may include from about 91.2 wt % to about 94.7 wt %aluminum, from about 3.8 wt % to about 4.9 wt % copper, from about 1.2wt % to about 1.8 wt % magnesium, and from about 0.3 wt % to about 0.9wt % manganese.

The aluminum alloy may include from about 91.2 wt % to about 94.7 wt %aluminum, from about 3.8 wt % to about 4.9 wt % copper, from about 1.2wt % to about 1.8 wt % magnesium, and from about 0.3 wt % to about 0.9wt % manganese.

The metal matrix composite formed according to the method may comprisefrom about 15 vol % to about 40 vol % of the reinforcement particles.

These and other non-limiting characteristics of the disclosure are moreparticularly disclosed below.

BRIEF DESCRIPTION OF THE DRAWINGS

The following is a brief description of the drawings, which arepresented for the purposes of illustrating the exemplary embodimentsdisclosed herein and not for the purposes of limiting the same.

FIG. 1 is a flow chart illustrating a non-limiting example of a methodfor producing a metal matrix composite and an article according to thepresent disclosure.

FIG. 2 is a photograph illustrating a brake disc article comprising analuminum matrix composite with fine reinforcement particles according toone embodiment of the present disclosure.

FIG. 3 is a photograph illustrating a chain ring article comprising analuminum matrix composite with fine reinforcement particles according toone embodiment of the present disclosure.

FIG. 4 is a photograph illustrating a close-up view of the chain ringarticle of FIG. 3 comprising an aluminum matrix composite with finereinforcement particles according to one embodiment of the presentdisclosure.

FIG. 5 is a graph showing the 0.2% offset yield strength versus theparticle size for two different loadings of silicon carbide particles.The y-axis is in units of MPa, and runs from 300 to 700 in intervals of50. The x-axis is in units of microns, and is semi-log with units of0.1, 1, 10, and 100 microns.

FIG. 6 is a graph showing the 0.2% offset yield strength versus thefracture toughness, showing predicted and actual values. The y-axis isin units of MPa, and runs from 300 to 600 in intervals of 50. The x-axisis in units of MPam^(1/2), and runs from 10 to 26 in intervals of 2.

DETAILED DESCRIPTION

A more complete understanding of the components, processes andapparatuses disclosed herein can be obtained by reference to theaccompanying drawings. These figures are merely schematicrepresentations based on convenience and the ease of demonstrating thepresent disclosure, and are, therefore, not intended to indicaterelative size and dimensions of the devices or components thereof and/orto define or limit the scope of the exemplary embodiments.

Although specific terms are used in the following description for thesake of clarity, these terms are intended to refer only to theparticular structure of the embodiments selected for illustration in thedrawings, and are not intended to define or limit the scope of thedisclosure. In the drawings and the following description below, it isto be understood that like numeric designations refer to components oflike function.

The singular forms “a,” “an,” and “the” include plural referents unlessthe context clearly dictates otherwise.

As used in the specification and in the claims, the term “comprising”may include the embodiments “consisting of” and “consisting essentiallyof.” The terms “comprise(s),” “include(s),” “having,” “has,” “can,”“contain(s),” and variants thereof, as used herein, are intended to beopen-ended transitional phrases, terms, or words that require thepresence of the named components/steps and permit the presence of othercomponents/steps. However, such description should be construed as alsodescribing compositions or processes as “consisting of” and “consistingessentially of” the enumerated components/steps, which allows thepresence of only the named components/steps, along with any impuritiesthat might result therefrom, and excludes other components/steps.

Numerical values in the specification and claims of this applicationshould be understood to include numerical values which are the same whenreduced to the same number of significant figures and numerical valueswhich differ from the stated value by less than the experimental errorof conventional measurement technique of the type described in thepresent application to determine the value.

All ranges disclosed herein are inclusive of the recited endpoint andindependently combinable (for example, the range of “from 2 to 10” isinclusive of the endpoints, 2 and 10, and all the intermediate values).

The term “about” can be used to include any numerical value that canvary without changing the basic function of that value. When used with arange, “about” also discloses the range defined by the absolute valuesof the two endpoints, e.g. “about 2 to about 4” also discloses the range“from 2 to 4.” The term “about” may refer to plus or minus 10% of theindicated number.

The present disclosure relates to materials having an average particlesize. The average particle size is defined as the particle diameter atwhich a cumulative percentage of 50% (by volume) of the total volume ofparticles are attained. In other words, 50 vol % of the particles have adiameter above the average particle size, and 50 vol % of the particleshave a diameter below the average particle size.

The use of particle reinforced aluminum alloys for brake discs is wellknown, but such alloys contain particles having large sizes of greaterthan 15 microns (μm). Such relatively large reinforcement particle sizespresent difficulties in machining, particularly the speed with whichsuch metal matrix composite materials can be machined, as well as thetolerances associated with the machined product. Certain articles havecomplex and difficult profiles to machine, especially when the ceramicreinforcement is coarse. It is considered to be almost impossible tomachine compositions with reinforcement particle sizes of 15 microns(μm). Even at a particle size of 7 μm, tool wear issues make achieving asuitable surface finish very difficult, and not economical.

The present disclosure relates to articles machined or otherwisemanufactured from metal matrix composite materials which include areinforcement phase dispersed in a matrix phase. The matrix phaseincludes aluminum or an aluminum alloy. The reinforcement phase isformed from a reinforcement material having an average particle size inthe range of from about 0.3 μm to about 5 μm. The disclosure alsorelates to methods for producing and using the composite materials.Because the reinforcement particles are finer, tool wear issues arereduced, making articles easier to machine.

Particle-reinforced aluminum alloys offer an increased elastic modulusas a function of the vol % or reinforcement material added. Existingmaterials offer medium strength levels. However, greater strength isdesirable for many applications (particularly in space, defense,aerospace, and transportation applications). The refinement ofreinforcement particles provides the potential for high-strengthmaterials without negatively impacting secondary properties (e.g.,ductility).

Reinforcement fibers having an average particle size in the range offrom about 0.3 μm to about 5 μm offer enhanced strength over coarsergrades. The finer reinforcement materials allow the production ofcomposite materials that can be machined faster with conventional toolsand with low tool wear. For example, the finer reinforcement materialsoffer advantages in forming processes (e.g., extrusion) to very closeprecision shapes without tool wear, thereby allowing use of conventionaltools (e.g., steel H13 dies). That is, the finer reinforcement sizesallow machining capability using high speed techniques to make partswith fine finish and tolerances. The addition of the fine reinforcementparticles offers a major increase in the wear resistance combined with agood balance of strength, stiffness, ductility and fatigue properties.This combines the mechanical properties needed for disc and rotorcomponents with the ability to process and machine in a cost effectivemanner.

The finer reinforcement materials also allow high-strength to beachieved in heat treatments that allow low residual stress (highstability) conditions.

The finer reinforcement materials may also allow enhanced elevatedtemperature properties and/or strength stability after soaking at mediumand high temperatures.

When low and medium strength 2xxx and 6xxx aluminum alloys are utilizedas the matrix alloy, their strengths can be increased to levelsequivalent to or greater than 7xxx aluminum alloys.

Good corrosion and stress corrosion performance can be achieved as aresult of the lower solute content matrix alloys. This results instrength and modulus increases which are useful for designinglightweight structural components.

The composite material may include from about 15 vol % to about 45 vol %of the reinforcement particles, including from about 17 vol % to about40 vol % and from about 20 vol % to about 25 vol %.

In some embodiments, the aluminum alloy includes from about 91.2 wt % toabout 94.7 wt % aluminum, from about 3.8 wt % to about 4.9 wt % copper,from about 1.2 wt % to about 1.8 wt % magnesium, and from about 0.3 wt %to about 0.9 wt % manganese.

In other embodiments, the aluminum alloy includes from about 95.8 wt %to about 98.6 wt % aluminum, from about 0.8 wt % to about 1.2 wt %magnesium, and from about 0.4 wt % to about 0.8 wt % silicon.

The aluminum alloy may be 2124. The composition of 2124 aluminum alloyis as follows:

Component Wt % Aluminum 91.2-94.7 Chromium Max 0.1 Copper  3.8-4.9 IronMax 0.3 Magnesium  1.2-1.8 Manganese  0.3-0.9 Other, each Max 0.05Other, total Max 0.15 Silicon Max 0.2 Titanium Max 0.15 Zinc Max 0.25

The reinforcement particles may include at least one material selectedfrom carbides, oxides, silicides, borides, and nitrides. In someembodiments, the material is selected from silicon carbide, titaniumcarbide, boron carbide, silicon nitride, titanium nitride, aluminumoxide, and zirconium oxide. Again, the reinforcement particles have anaverage particle size of from about 0.3 microns to about 5 microns,including from about 0.3 microns to about 3 microns.

FIG. 1 is a flow chart illustrating an exemplary method 100 of thepresent disclosure. The method includes providing metal particles (e.g.,aluminum or aluminum alloy particles) 105 and providing reinforcementparticles (e.g., ceramic particles) 110 to a high energy mixing stage120.

The metal and ceramic powders should be mixed with a high energytechnique to distribute the ceramic reinforcement particles into themetal matrix. Suitable techniques for this mixing include ball milling,mechanical attritors, teamer mills, rotary mills and other methods toprovide high energy mixing to the powder constituents. Mechanicalalloying should be completed in an atmosphere to avoid excessiveoxidation of powders preferable in an inert atmosphere using nitrogen orargon gas. The processing parameters should be selected to achieve aneven distribution of the ceramic particles in the metallic matrix.

The powder from the high energy mixing stage 120 is compacted 130.Compaction 130 may include one, two, or more steps. In some embodiments,compaction 130 includes a cold (e.g., room temperature) compaction stepwhich forms a preform a desired shape. The cold compacting coalesces theparticles and increases density. However, the preform is not close tofully dense. In particular embodiments, the cold compacting is performedusing a tool diameter of about 50 mm to about 70 mm, with a load ofabout 80 tons to about 90 tons. In other embodiments, the coldcompacting is performed using a tool diameter of about 50 mm to about 70mm, with an exerted pressure of about 250 MPa to about 330 MPa.

The powder from the high energy mixing stage is degassed to remove anyretained moisture from the powder surface, this may be completed atbetween 120 to 500° C.

A hot compacting step may also be performed to increase density andproduce a billet 140. The hot compacting may be performed at atemperature in the range of from about 400° C. to about 600° C.,including from about 425° C. to about 550° C. and about 500° C. Hotcompaction may include the use of hot die compaction, hot isostaticpressing or hot extrusion typically at pressures of between 30 to 150MPa.

In particular, hot isostatic pressing is contemplated for making thebillet. In the HIP process, the powder is exposed to both elevatedtemperature and high gas pressure in a high pressure containment vessel,to turn the powder into a compact solid, i.e. a billet. The isostaticpressure is omnidirectional. The HIP process eliminates voids and pores.The hot isostatic pressing may be performed at a temperature of 1000° C.to 1200° C. and a pressure of 30 to 150 MPa for a period of sufficientto allow the metal section to reach the required temperature, typicallybetween 1 and 8 hours. The hot isostatic pressing may be performed oncommercially available steel or nickel HIP systems.

The billet may be subsequently processed 150 into a final article. Thisprocessing may include rolling, extrusion, or machining, without hotworking. In accordance with one embodiment, the billet is rolled orextruded into an intermediate article. Final machining, e.g., CNC, isperformed on the intermediate article resulting in a final article suchas a rotor, disc, chain ring, or sprocket.

The resulting articles have high wear resistance. It is particularlycontemplated that the articles of the present disclosure have smallcross-sections which must withstand high stresses for long periods oftime. In embodiments, the articles have a thickness of about 1millimeter (mm) to about 10 mm. Parts of the articles also have sectionswith a width of about 1.5 mm to about 5 mm. For example, toothedarticles such as gears, sprockets, and chain rings have teeth with suchwidths and thicknesses. In particle, articles contemplated by thepresent disclosure include articles formed from an annular structuralmember having teeth pointing outwards radially and distributed about theouter circumference of the annular structural member. Also contemplatedare discs that are formed from an annular structural member and havingvarious holes and patterns punched through the annular structuralmember. Examples of such articles are seen in FIG. 2 and FIG. 3.

The resulting articles may have a 0.2% offset yield strength of about400 MPa to about 680 MPa; an elastic modulus of about 80 GPa to about150 GPa; or about 3% to about 8% elongation to failure, as measuredaccording to ASTM E8M. Combinations of these properties are alsospecifically contemplated. The articles have a balance of high strengthand high elastic modulus with good ductility.

FIG. 5 is a graph showing the effect of the particle size on the 0.2%offset yield strength. Briefly, as the particle size decreases, the 0.2%offset yield strength increases, regardless of the amount ofreinforcement particles in the metal matrix composite.

FIG. 6 is a graph showing unexpected results. The graph shows the 0.2%offset yield strength versus the fracture toughness of the metal matrixcomposite. The x-axis is a measure of the resistance of the material tothe propagation of a crack. The yield strength for a metal matrixcomposite made of 2124 aluminum and 17 vol % of SiC particles with aparticle size of 0.3 μm was almost 100 MPa higher than expected.

The following examples are provided to illustrate the compositions,articles, and methods of the present disclosure. The examples are merelyillustrative and are not intended to limit the disclosure to thematerials, conditions, or process parameters set forth therein.

EXAMPLES Example 1 Brake Disc (FIG. 2)

FIG. 2 provides a photograph illustrating a brake disc comprised of analuminum matrix composite material having reinforcement particles in therange of 0.3 pm to 3 μm. The disc was high speed machined usingconventional milling and turning processes in the same time.

Example 2 Chain Ring (FIG. 3 and FIG. 4)

FIG. 3 illustrates a photograph of a chain ring comprised of an aluminummatrix composite material having reinforcement particles in the range of0.3 μm to 3 μm. FIG. 4 illustrates a photograph of a close-up view ofthe chain ring of FIG. 3 comprised of the aforementioned aluminum matrixcomposite material.

Example 3

A pin-on-disc wear test was conducted according to ASTM G99. The pinswere ⅜-inch in diameter, and the disc was 1.5 inches in diameter. Theconditions were 23° C., 36% relative humidity. The wear cycle frequencywas 2 Hz, and the wear pattern was a 15 mm unidirectional path. Thetests were performed at loads of 20 newtons (N), 35 N, 50 N, and 65 N.The test duration was 5000 cycles for the 65 N load, and 10,000 cyclesfor the 20 N, 35 N, and 50 N loads. The contact area between the pin andthe disc was 71.26 mm². The weight loss on the disc and the pin weremeasured.

The discs were made of 2124 aluminum containing 25 vol % SiCreinforcement particles. The SiC particles had particle sizes of either3 microns or 0.7 microns. The discs were either heat treated to T4 or T6specifications. For T4, the disc was solution treated at 505° C.followed by quenching using water or polymer glycol, then naturally agedat room temperature for more than 24 hours. For T6, the disc wassolution treated at 505° C. followed by quenching using water or polymerglycol, then artificially aged at 150° C. for 1 hour. Results are shownin the following Tables A and B:

TABLE A Disc Mass Loss Load (N) 20 N 35 N 50 N 65 N Sliding Distance(km) 0.3 Km 0.3 Km 0.3 Km 0.15 Km Cycles 10000 10000 10000 5000 DiscMass Disc Mass Disc Mass Disc Mass Disc Material Pin Material Loss (mg)Loss (mg) Loss (mg) Loss (mg) 2124/SiC/25% 2124/SiC/25% 2.9 9.7 3.4 1.8(3 micron) T4 (3 micron) T4 2124/SiC/25% 4340 Steel 1.5 4 6.2 2.6 (3micron) T4 2124/SiC/25% 4340 Steel 3.1 14.2 16.2 35.8 (0.7 micron) T6300M Steel 4340 Steel 97.3 42.4 104.1 80.4

TABLE B Pin Mass Loss Load (N) 20 N 35 N 50 N 65 N Sliding Distance (km)0.3 Km 0.3 Km 0.3 Km 0.15 Km Cycles 10000 10000 10000 5000 Pin Mass PinMass Pin Mass Pin Mass Disc Material Pin Material Loss (mg) Loss (mg)Loss (mg) Loss (mg) 2124/SiC/25% 2124/SiC/25% 0.5 0.8 0.4 0.2 (3 micron)T4 (3 micron) T4 2124/SiC/25% 4340 Steel 0.5 0.8 0.6 0.4 (3 micron) T42124/SiC/25% 4340 Steel 0.6 0.7 0.7 0.1 (0.7 micron) T6 300M Steel 4340Steel 213.3 100 278.2 230.6

As seen in Tables A and B, the use of the metal matrix composites forthe disc significantly reduced wear in both the disc and the pin,compared to the test where both materials were steel.

Although not shown, a further example is a motorcycle sprocket, whichcan suffer substantial wear against the drive chain, as well as fromgrit and mud causing abrasive wear on the sprockets. Aluminum matrixcomposite fine particle reinforced aluminum alloys by Materion® offer asignificant enhancement in wear properties and provide significant lifeand sprocket performance improvement over conventional aluminumsprockets. This has to be combined with high strength to avoid toothdeformation, sufficient ductility to deal with robust usage, lightweightcharacteristics and an ability to manufacture the components. Thesecharacteristics will also apply to bicycle chain rings. There can alsobe some application for lightweight brake discs.

The manufacture of aluminum alloys with finer reinforcement sizes of 5μm down to 0.3 μm in accordance with the methods and materials describedherein, particularly the finer reinforcement sizes, allow machiningcapability using high speed techniques to make parts with fine finishand tolerances. The addition of the fine reinforcement offers a majorincrease in the wear resistance combined with a good balance ofstrength, stiffness, ductility and fatigue properties. This combines themechanical properties needed for disc, rotor, chain ring, and sprocketcomponents with the ability to process and machine in a cost effectivemanner.

The present disclosure has been described with reference to exemplaryembodiments. Obviously, modifications and alterations will occur toothers upon reading and understanding the preceding detaileddescription. It is intended that the present disclosure be construed asincluding all such modifications and alterations insofar as they comewithin the scope of the appended claims or the equivalents thereof.

1. An article formed from a metal matrix composite, the metal matrixcomposite comprising: an aluminum or aluminum alloy matrix; andreinforcement particles dispersed in the matrix, the reinforcementparticles having an average size in the range of from about 0.3 μm toabout 5 μm.
 2. The article of claim 1, wherein the article is a brakedisc, a rotor, a sprocket or a chain ring.
 3. The article of claim 1,wherein the article has a thickness of about 1 mm to about 10 mm.
 4. Thearticle of claim 1, wherein the article has teeth, each tooth having awidth of about 1.5 mm to about 5 mm.
 5. The article of claim 1, whereinthe reinforcement particles comprise at least one ceramic materialselected from the group consisting of carbides, oxides, silicides,borides, and nitrides.
 6. The article of claim 1, wherein thereinforcement particles comprise at least one ceramic material selectedfrom the group consisting of silicon carbide, titanium carbide, boroncarbide, silicon nitride, titanium nitride, aluminum oxide, andzirconium oxide.
 7. The article of claim 1, wherein the aluminum alloycomprises at least one element selected from the group consisting ofchromium, copper, lithium, magnesium, manganese, nickel, zinc, iron,vanadium, scandium, silver, and silicon.
 8. The article of claim 1,wherein the aluminum alloy comprises from about 91.2 wt % to about 94.7wt % aluminum, from about 3.8 wt % to about 4.9 wt % copper, from about1.2 wt % to about 1.8 wt % magnesium, and from about 0.3 wt % to about0.9 wt % manganese.
 9. The article of claim 1, wherein the aluminumalloy comprises from about 95.8 wt % to about 98.6 wt % aluminum, fromabout 0.8 wt % to about 1.2 wt % magnesium, and from about 0.4 wt % toabout 0.8 wt % silicon.
 10. The article of claim 1, wherein thecomposite comprises from about 15 vol % to about 40 vol % of thereinforcement particles.
 11. The article of claim 1, having a 0.2%offset yield strength of about 400 MPa to about 680 MPa; an elasticmodulus of about 80 GPa to about 150 GPa; and about 3% to about 8%elongation to failure, measured according to ASTM E8M.
 12. A method forproducing an article from a metal matrix composite material, comprising:cold compacting the metal matrix composite material to form a preform;hot compacting the preform to produce a billet; and processing thebillet to form the article; wherein the metal matrix composite materialcomprises an aluminum or aluminum alloy matrix material withreinforcement particles dispersed therein, the reinforcement particleshaving an average size of about 0.3 μm to about 5 μm.
 13. The method ofclaim 12, wherein the billet is processed by machining to obtain adesired shape.
 14. The method of claim 12, wherein the article isselected from the group consisting of a disc, a rotor, a chain ring or asprocket.
 15. The method of claim 12, wherein the article has athickness of about 1 mm to about 10 mm.
 16. The method of claim 12,wherein the article has teeth, each tooth having a width of about 1.5 mmto about 5 mm.
 17. The method of claim 12, wherein the reinforcementparticles comprise at least one ceramic material selected from the groupconsisting of silicon carbide, titanium carbide, boron carbide, siliconnitride, titanium nitride, aluminum oxide, and zirconium oxide.
 18. Themethod of claim 12, wherein the aluminum alloy comprises at least oneelement selected from the group consisting of chromium, copper, lithium,magnesium, manganese, nickel, zinc, iron, vanadium, scandium, silver,and silicon.
 19. A method of using an article, comprising: engaging anouter circumference of the article with a chain; wherein the article isformed from a metal matrix composite comprising: an aluminum or aluminumalloy matrix; and reinforcement particles dispersed in the matrix, thereinforcement particles having an average size in the range of fromabout 0.3 μm to about 5 μm.
 20. A method for making a metal matrixcomposite material, comprising: high energy mixing metal particles withceramic reinforcement particles; wherein the metal particles comprise analuminum or aluminum alloy; and wherein the ceramic reinforcementparticles have an average size of about 0.3 μm to about 5 μm.